You can find more information on how to initialize WorkflowDesginer's JS object and required libraries here.

Besides, you can have a look at an example of integrating Workflow Desginer into an Angular application on GitHub.

This sample uses the resources and the server-side of our demo stand available at workflowengine.io. You need to turn on CORS in your browser for the sample to work properly. You can do that via a Chrome extension. Use a search engine to look for solutions for other browsers.